Prospective evaluation of the risk of bacteremia induced by transesophageal echocardiography

BACKGROUND: The incidence of bacteremia induced by transesophageal echocardiography is controversial in the Indian population. This study aimed to find out the occurrence of bacteremia following transesophageal echocardiography. METHODS AND RESULTS: Between February 2000 and January 2001, 47 patients (26 males and 21 females) were enrolled for the study. Their ages ranged from 13 to 61 years (mean: 35 +/- 11.4 years). Patients with prosthetic valves, suspected infective endocarditis and those on antibiotics were excluded. For each procedure, two sets of blood cultures were obtained immediately before and after the procedure. For each blood culture, 10 ml of blood was evenly inoculated into brain-heart infusion broth and biphasic infusion medium and incubated for 7 days. Transesophageal echocardiography was carried out under oropharyngeal anesthesia (xylocaine gel and spray). Two blood cultures taken before the procedure were positive and excluded from the final analysis. Of the remaining 45 patients whose preprocedure blood cultures were sterile, 6 samples (13.3%) were positive after the procedure diphtheroids in 3, micrococci in 2 and aerobic spore formers in 1. CONCLUSIONS: This study demonstrates that the incidence of bacteremia related to transesophageal echocardiography is not insignificant, as reported in previous studies. Though routine antibiotic prophylaxis before transesophageal echocardiography is not advocated, it should be recommended in high-risk patients such as those with prosthetic valves, multivalvular involvement or those with a past history of infective endocarditis.     

Importance of transesophageal echocardiography in the evaluation of Staphylococcus aureus bacteremia

BACKGROUND AND AIM OF THE STUDY: Staphylococcus aureus is a leading cause of bacteremia and is often associated with endocarditis. The diagnosis of endocarditis may be missed when relying on clinical risk prediction, and this has led others to recommend transesophageal echocardiography (TEE) for diagnosis in most cases of S. aureus bacteremia (SAB). The study aim was to determine the likelihood of finding vegetations on TEE in patients with SAB in a suburban teaching hospital setting, and to identify risk factors predictive of vegetation on TEE. METHODS: All cases of SAB at Walter Reed Army Medical Center between January 2000 and May 2003 were evaluated. The prevalence of vegetations was determined in those cases selected for TEE. Potential risk factors for endocarditis were analyzed by review of medical records. RESULTS: A total of 176 patients had documented SAB during the time frame of the study, and 64 of these had TEE performed. Among the latter patients, 14% had a previously unidentified vegetation discovered by TEE. Patients with vegetation on TEE were as likely as those without vegetation to have nosocomial bacteremia, an alternate source of infection, and lack of valvular disease by prior surface echocardiography. Patients with a vegetation were significantly older (mean age 68.4+/-10.9 versus 54.6+/-19.6 years; p = 0.04). CONCLUSION: TEE identified a significant number of vegetations resulting from SAB. The clinical risk profile and transthoracic echocardiography did not reliably exclude vegetation. These findings support the liberal use of TEE for the diagnosis of SAB.     

Prospective study of blood culture during transesophageal echocardiography.

To ascertain the incidence and significance of bacteremia associated with transesophageal echocardiography (TEE), 132 consecutive patients (aged 17 to 73 years) free of apparent infection who were undergoing 135 transesophageal echocardiographic procedures from October 1990 to August 1991, were prospectively studied. For each procedure, two sets of blood cultures were obtained for culture 30 to 60 minutes before TEE, immediately after, and 180 to 240 minutes after the procedure. For each blood culture, 10 ml of venous blood was evenly inoculated into aerobic and anaerobic culture bottles and inoculated for 7 days using a radiometric system. A throat swab was obtained immediately before each procedure. Three of 270 preprocedure blood cultures were positive for Bacillus cereus, Staphylococcus simulans, and Peptostreptococcus species, respectively. No blood culture was positive in the immediate postprocedure period. Two of 270 late blood samples grew Staphylococcus epidermidis in the same patient. Nevertheless, the microorganisms isolated from blood cultures were different from those isolated from the throat swab. No patients had fever or evidence of infective endocarditis after TEE during the follow-up period. It is concluded that the incidence of TEE-related bacteremia is extremely low, and a general recommendation for antibiotic prophylaxis during TEE is not warranted.     

Role of transesophageal echocardiography in the evaluation of patients with stroke

This review article summarizes recent advances in the care of patients presenting with neurologic events, in which transesophageal echocardiography plays an important role in diagnosis, prognosis, and treatment. New research on the use of transesophageal echocardiography in patients with stroke and atrial fibrillation is discussed, including left atrial clot formation, maintenance of sinus rhythm after cardioversion, and techniques of left atrial appendage occlusion. A discussion of developments in the diagnosis and management of thoracic aortic plaque follows. The association of patent foramen ovale and atrial septal aneurysm with stroke is outlined, and possible reasons for this association are discussed. Recent literature on the use of percutaneous closure devices for patent foramen ovale is reviewed.     

Prospective assessment of risk of bacteremia with colonoscopy and polypectomy

A prospective assessment was made of the frequency of positive blood cultures in patients undergoing colonoscopy with or without polypectomy. A total of 270 patients underwent 280 colonoscopies, of these, there were 105 patients that had 111 polypectomies. Blood cultures were taken prior to and within 15 min following each procedure. Six of 280 (2.1%) preprocedural blood cultures were positive. Seven of 169 (4%) blood cultures were positive within 15 min of insertion of the colonoscope in the colonoscopy only group. Eight of 223 (3.6%) blood cultures were positive within 10 min of the polypectomy. There was no clinical evidence of sepsis during the 24 hr following these procedures. In order to determine appropriate postprocedural sampling interyals, we induced aStaphylococcus epidermidis bacteremia with a mean of 1.16×10⁶ colony forming units/ml on 10 occasions in seven dogs. Within 30 min of inoculation, we were able to detect only one colony forming unit/ml. The rate of positive blood cultures during colonoscopy alone and following polypectomy during colonoscopy is comparable to other gastrointestinal endoscopy procedures. The most optimal time to collect blood cultures in order to detect transient bacteremia is as soon after the procedure as is feasibly possible.This research was supported in part by grants from the Victoria General Hospital Research Foundation, Inc., and the Manitoba Heart Foundation.     

Left pulmonary artery evaluation through transesophageal echocardiography.

INTRODUCTION: Transesophageal echocardiography (TEE) has become increasingly useful in the study of patients with suspected pulmonary thromboembolism. OBJECTIVE: The aim of this study was to prospectively evaluate the usefulness of TEE in the study of the distal part of the left pulmonary artery (LPA) as well as the influence of this procedure on total echocardiographic exam duration. METHODOLOGY: A prospective study in two groups of consecutive patients referred for TEE with a one- year interval between evaluation of Group A: 33 patients, 17 male, mean age 54 +/- 24 years, and Group B: 42 patients, 20 male, mean age 48 +/- 27 years (p = NS). The procedure was considered long when it took more than 3 min to evaluate the distal part of the LPA. RESULTS: In group A we were able to visualize the distal part of the LPA in 24 patients (73%) without significant prolongation of total exam duration in 16 patients (48% of group A). In one of the patients with suspected pulmonary thromboembolism thrombi were only observed in the distal part of the LPA. In group B we were able to visualize the distal part of the LPA in 36 patients (86%) without significant prolongation of total exam duration in 26 patients (61% of group B). CONCLUSIONS: 1. Visualization of the distal part of the LPA was possible in more patients, and with TEE time prolongation in less patients, in group B. These differences can be accounted for by the training of the operator in this technique. 2. The importance of visualization of this part of the LPA in guiding treatment in the subset of patients with pulmonary thromboembolism confirms the usefulness of this specific procedure.     

Incidence of bacteremia in transesophageal echocardiography: a prospective study of 140 consecutive patients

The incidence of bacteremia related to transesophageal echocardiography was studied in 140 consecutive patients (71 women and 69 men with a mean age of 53.7 +/- 15 years). Thirty-four patients had one or more prosthetic heart valves. Blood cultures were obtained from each patient through separate venipuncture sites immediately before and after transesophageal echocardiography. An additional late blood culture was obtained in 114 patients 1 h later. The skin was cleaned with povidone-iodine and venipunctures were performed with separate butterfly needles with use of sterile gloves and drapes. Blood samples were drawn into separate syringes, transferred to aerobic and anaerobic culture bottles and processed with use of a semiautomated system. The overall incidence of blood cultures positive for bacteremia was 2% (8 of 394 bottles) and all positive cultures grew in a single blood culture bottle. Positive cultures occurred in 4 (1.4%) of 280 bottles before the procedure, in 2 (0.7%) of 280 bottles immediately after the procedure and in 2 (0.9%) of 228 late (1-h) blood culture bottles. Bacterial isolates were coagulase-negative staphylococci (n = 5), Propionibacterium (n = 2) and Moraxella (n = 1). All were considered contaminants. Mean endoscopic time in these patients was not significantly different from that in the other patients. Follow-up of patients with a blood culture positive for bacteremia revealed no clinical evidence of systemic infection. It is concluded that 1) the incidence of bacteremia related to transesophageal echocardiography is very low, and 2) the incidence of blood cultures positive for bacteremia after transesophageal echocardiography is indistinguishable from the anticipated contamination rate.     

Complications of transesophageal echocardiography with dobutamine

The transesophageal echocardiographic approach improves the diagnostic power of transthoracic stress echocardiography. However, it is a seminvasive test and its safety is not well established. Our objective was to compare the incidence of complications of transesophageal and transthoracic dobutamine echocardiography. We collected data from 63 patients with inadequate transthoracic window, who underwent transesophageal dobutamine echocardiography and were compared with 100 patients in whom the transthoracic approach was diagnostic. Baseline blood pressure and heart rate were higher in the first group. There were no differences in those parameters at the end of the test. Neither were atropine administration and side effects more frequent in any of the groups. There were no cases of ventricular fibrillation, ventricular tachycardia, acute myocardial infarction, intractable angina or intolerance to the probe. Side effects were equally present in both groups. Transesophageal dobutamine stress echocardiography is a safe test that can be used in patients with coronary artery disease and poor transthoracic window.     

Cardiac arrest associated with intravenous propofol during transesophageal echocardiography before DC cardioversion

Transesophageal echocardiography (TEE)-guided cardioversion has been utilized as a feasible alternative to conventional anticoagulation strategies in the management of patients with atrial fibrillation. As such, the use of intravenous sedation protocols using relatively short-acting anesthetics, such as propofol, have gained popularity in the outpatient and inpatient settings for such procedures. The authors report a case of cardiac arrest and electromechanical dissociation associated with the use of intravenous propofol during TEE before direct current cardioversion for atrial fibrillation.     

Isolated subclavian artery aneurysm: evaluation by transesophageal echocardiography

A 50-year-old man was evaluated following a motor vehicle accident. Chest X-ray showed a widened mediastinum. Transesophageal echocardiography was helpful in identifying the left subclavian artery and in demonstrating an isolated subclavian artery aneurysm. The TEE findings correlated well with the results of chest CT. Using TEE for the identification of the aortic branches in patients with chest trauma may be critical.     

Retrospective evaluation of the clinical characteristics associated with Corynebacterium species bacteremia

Objectives

Corynebacterium spp. are becoming recognized as pathogens that potentially cause various infections. We aimed to evaluate the clinical characteristics associated with Corynebacterium spp. bacteremia.

Cost-effectiveness of transesophageal echocardiography to determine the duration of therapy for intravascular catheter-associated Staphylococcus aureus bacteremia.

BACKGROUND: The appropriate duration of therapy for catheter-associated Staphylococcus aureus bacteremia is controversial. Conventional practice dictates that all patients receive prolonged courses of intravenous antibiotics. Some clinicians recommend abbreviated therapeutic courses, but an alternate approach involves prospectively identifying patients for whom abbreviated therapy is appropriate. OBJECTIVE: To determine the cost-effectiveness of transesophageal echocardiography (TEE) in establishing duration of therapy for catheter-associated S. aureus bacteremia. DESIGN: Cost-effectiveness analysis. DATA SOURCES: MEDLINE search of literature; clinical data from patients with S. aureus bacteremia (n = 196) and patients with endocarditis (n = 60); and costs obtained from the study institution, regional home health agency, and national estimates of professional and technical fees. TARGET POPULATION: Patients with catheter-associated S. aureus bacteremia on native heart valves without intravenous drug use or clinically apparent metastatic infection, immunosuppression, or indwelling prosthetic devices. TIME HORIZON: Patient lifetime. PERSPECTIVE: Societal. INTERVENTIONS: Antibiotic treatment based on TEE results compared with 2- or 4-week empirical therapy. OUTCOME MEASURES: Quality-adjusted life expectancy, costs, and incremental cost-effectiveness ratios. RESULTS OF BASE-CASE ANALYSIS: Compared with empirical short-course therapy, the TEE strategy cost $4938 per quality-adjusted life-year (QALY) gained. The effectiveness of the TEE strategy and the effectiveness of the long-course strategy were sufficiently similar that the additional cost of empirical long-course therapy ($1,667,971 per QALY) was higher than that which society usually considers cost-effective. RESULTS OF SENSITIVITY ANALYSES: In a four-way sensitivity analysis (endocarditis prevalence, TEE cost, short-course relapse rate, and TEE specificity), compared with empirical short-course therapy, the TEE strategy results ranged from cost savings to $155,624 per QALY. CONCLUSION: Within the limitations of existing empirical data, this study suggests that for patients with clinically uncomplicated catheter-associated S. aureus bacteremia, the use of TEE to determine therapy duration is a cost-effective alternative to 2- or 4-week empirical therapy.     

Intraoperative transesophageal echocardiography for evaluation of mitral valve repair.

BACKGROUND AND AIM OF THE STUDY: Although mitral valve repair is a well-established procedure, incorrect assessment of the repaired valve may occasionally lead to the need for reoperation. This study was performed to evaluate the accuracy of color Doppler in assessing the competence of the repaired mitral valve. METHODS: Transesophageal echocardiography (TEE) and left ventriculography were each performed in 72 patients to compare the two techniques and a semi-quantitative index derived. Using this relationship, post bypass intraoperative TEE was then performed in 34 patients who underwent mitral valve repair, in order to assess the competence of the repaired valve. RESULTS: Significant differences were apparent in maximal regurgitant mosaic area between angiographic grade 0, and grades 1+ (p = 0.0006), 1+ and 2+ (p < 0.0001) and 2+ and 3+ (p = 0.0010). A maximal regurgitant area < 2 cm2 predicted angiographic grade as 0 (sensitivity 100%, specificity 95%), an area of 2-4 cm2 as 1+ (sensitivity 82%, specificity 100%), an area of 4-7 cm2 as 2+ (sensitivity 78%, specificity 90%), and an area > 7 cm2 as grade 3+ or 4+ (sensitivity 79%, specificity 93%). All 34 patients completed valve repair with the maximal regurgitant mosaic area < 2.5 cm2. Postoperative left ventriculography showed grade +1 in only five patients; four of these completed mitral valve repair with a maximal mosaic area > 2.0 cm2 as assessed by post bypass intraoperative TEE. During follow up, transthoracic echocardiography (TTE) detected recurrent mitral regurgitation which required mitral valve replacement in one patient, and rapid progression of mitral regurgitation in three patients. CONCLUSIONS: It is important that mitral valve repair should be completed with a maximal mosaic area < 2.0 cm2 as assessed by intraoperative TEE, in order to reduce the need for reoperation.     

Routine transesophageal echocardiography for the evaluation of cerebral emboli in elderly patients

BACKGROUND: Approximately 20% of cerebral infarctions are cardioembolic in nature. Transesophageal echocardiography (TEE) is widely regarded as the initial study of choice for evaluating cardiac source of embolism. Although the majority of cerebrovascular accidents occur in elderly patients, the value of TEE in this population is poorly defined. METHODS: We compared 491 patients older than 65 years with suspected embolic stroke or transient ischemic attack (TIA) who had undergone TEE evaluation between April 2000 and February 2004 to an age-, sex-, and time-matched control group that consisted of 252 patients. Studies were reviewed for abnormalities associated with thromboembolic disease. RESULTS: The overall incidence of stroke risk factors was significantly higher in the study than in the control group. However, the four patients with left atrial thrombi had a history of atrial fibrillation. Although ascending and aortic arch sessile atheromata were observed more frequently in the study than control group, there were no significant differences in the incidence of either complex or mobile aortic atheromata. The incidence of atrial septal aneurysm was higher in the stroke/TIA group, but not in association with patent foramen ovale. Finally, there were also no differences in the incidence of spontaneous echocontrast, and/or patent foramen ovale between study and control groups. CONCLUSIONS: We conclude: (1) There is a higher incidence of abnormalities implicated as sources of thromboembolic disease on TEE in elderly patients with cerebral infarctions, but (2) this incidence is driven by the presence of sessile aortic atheroma and atrial septal aneurysm. Until the benefits of specific therapies for these conditions are known, routine TEE in elderly patients with suspected embolic neurological events appears to be unwarranted.     

Papillary fibroelastoma of the aortic valve: evaluation with transesophageal echocardiography and magnetic resonance imaging

A 74-year-old Japanese male was admitted to hospital with episodes of chest pain. Cross-sectional echocardiography showed a mobile mass adherent to the noncoronary cusp of the aortic valve. We employed transesophageal echocardiography and magnetic resonance imaging to evaluate the mass. Based on the findings, a papillary fibroelastoma of the aortic valve was suspected. To avoid systemic embolization, urgent surgery was performed. The histopathologic diagnosis was papillary fibroelastoma. When a tumor of the aortic valve exists, these examinations are useful in detecting and characterizing the tumor for optimal treatment.     

Usefulness of transesophageal echocardiography in evaluation of paracardiac neoplastic masses.

Mediastinal paracardiac tumors may cause both cardiovascular complications and problems in differential diagnosis of cardiac diseases. Transesophageal echocardiography (TEE) may give an additional new window to mediastinal neoplasms, but only a few studies have been reported. TEE was performed in 70 patients with paracardiac neoplastic masses. The procedure was indicated to solve particular clinical problems in 20 patients, and as a prospective study on 50 unselected patients with mediastinal neoplasms. Twenty-three patients underwent follow-up studies; a total of 101 echocardiograms were recorded. The procedure was tolerated well or very well by most patients, and provided additional anatomic or hemodynamic data in every patient in group a and in 45 of 50 in group b. The additional data were relevant for clinical management in 14 of 20 patients in group a, and in 3 of 45 in group b. Based on the results of this study, TEE is useful in association with other radiologic techniques in patients with paracardiac neoplasms. As an imaging technique, it may represent a reliable alternative to computed tomography whenever the latter is not feasible.     

经食管三维超声心动图在二尖瓣位感染性心内膜炎中的应用

目的评价经食管三维超声心动图（three-dimensional transesophageal echocardiography,3D-TEE）在二尖瓣位感染性心内膜炎（infective endocarditis,IE）中的应用价值。方法选择2008年6月至2012年5月期间,在广东省人民医院行超声心动图检查并结合临床诊断,最终经手术病理确诊为二尖瓣位IE患者20例为研究对象。所有患者术前均行经胸超声心动图（transthoracic echocardiography,TTE）及3D-TEE检查。以病理为金标准,比较TTE及3D-TEE对诊断心内膜受累各种表现形式的敏感性和特异性。结果手术病理证实二尖瓣位赘生物20例,合并瓣膜穿孔11例,瓣周脓肿3例,瓣膜瘤2例,人工瓣撕脱3例。TTE及3D-TEE诊断赘生物的敏感性为80%vs.90%,特异性为57%vs.86%;诊断瓣膜穿孔的敏感性为72%vs.91%,特异性为78%vs.89%;诊断瓣周脓肿的敏感性为33%vs.66%,特异性为82%vs.94%;诊断瓣膜瘤的敏感性为50%vs.100%,特异性为94%vs.94%;诊断人工瓣撕脱的敏感性及特异性均为100%。3D-TEE对赘生物的检出率均高于TTE,差异有统计学意义（P〈0.05）。结论 3D-TEE对诊断IE各种表现形式均有较高的敏感性和特异性,能准确显示赘生物位置、形态、大小及其与周围心脏结构的空间关系,对临床治疗方案的选择及预后评估有重要作用。     

Follow-up of patients undergoing surgery for aortic dissection: evaluation with transesophageal echocardiography]

BACKGROUND. Transesophageal echocardiography (TEE) is a useful means in the diagnosis of acute aortic dissection (AD), owing to its very high sensibility and specificity. In this study, TEE was performed to assess post-surgical evolution. PATIENTS. Between 1982 and 1991, 119 pts. were operated on in our institution for AD (De Bakey I and II type): 87 pts. underwent replacement of the ascending aorta with a composite tubular graft bearing a mechanical valve; 26 had a simple tubular graft and 6 had aortic reconstruction. Sixty-eight of 72 discharged pts. were followed for up to 9.5 years (mean 4.5 +/- 2.6). Nine years after surgery actuarial survival of discharged pts. was 75%. Seven pts. died after a mean period of 3.4 years from surgery: only one died from postoperative complication (dehiscence of proximal anastomosis), none for aortic rupture distal to the graft. TEE was performed in 32 of these pts. and in other two operated on elsewhere, after 4.4 +/- 2.7 years from surgery; before the operation, type I AD was diagnosed in 23 pts. and type II in 11 pts. RESULTS. In 10/11 pts. with type II AD the aortic arch and the descending aorta looked normal; in one patient a localized intimal flap was found up to the arch. The descending aorta diameter was somewhat higher than in normal subjects (25.2 +/- 2.8 vs 21.9 +/- 3.7 mm), but in only one case was it beyond 2DS (32 mm). In all type I pts. an intimal flap persisted distal to the graft, along the whole thoracic aorta. Within the false lumen a flow was detected by color-Doppler in 14/23 pts. (61%), and spontaneous echo-contrast was noted in 14 pts. (61%). A thrombus was observed in 7 pts. (30%) and it was generally localized; in only one case it was extensive with total obliteration of the false lumen. In 16 pts. (70%) communications between the two lumina were found. The descending aorta diameter ranged from 25 to 53 mm, and mean value was higher than in normal subjects (34.2 +/- 6.2 vs 21.9 +/- 3.7 mm). CONCLUSIONS. In most pts. with type II AD, surgery can be a definitive treatment, as the remaining aorta keeps to normal size and appearance. In type I AD, operation is only palliative, as the dissection persists: the false lumen is often perfused through one or more communications with the true lumen and seldom its obliteration is noted. The persistence of dissection does not necessarily seem to be an ominous finding, as the survival of the study population was high and no patient died from aortic rupture. Nevertheless, long-term prognosis can be affected by aorta dilation that often (but not always) follows the persistence of wall dissection. For its high reliability, easy feasibility and low cost TEE is a very useful method for following up patients operated on for AD and for detecting those who are at higher risk of aortic rupture because of lumen dilation.     

Transvenous mitral commissurotomy examined with transesophageal echocardiography

Summary Transvenous mitral commissurotomy (TMC) was conducted with transesophageal echocardiography (TEE) in two patients with mitral stenosis. It was possible to see clearly not only the intracardiac structures to be examined by TMC, such as the right and left atria, interatrial septum, and mitral valve, but also the instruments used in TMC, such as the catheter, guidewire, and balloon. It was possible to determine the positional relation between the intracardiac structures and instruments. We could observe all procedures other than Brockenbrough's procedure by both TEE and fluoroscopy at the same time. Although safety and reliability cannot be confirmed from just the two present cases, TEE appears to be applicable to TMC.